Researchers from Florida Atlantic University's Harbor Branch Oceanographic Institute recently completed a 10-week study to determine the optimal growing conditions for three species of sea vegetables: sea asparagus (Salicornia bigelovii), sea purslane (Sesuvium portulacastrum) and saltwort (Batis maritima). These sea vegetables are eaten in Europe, Asia and Hawaii and could soon be a great addition to salads, soups, pasta, rice and other dishes in the continental United States.
These nutritious plants for human consumption do not require fresh water, instead being grown in salt water. They are halophyte plants or "salt-loving" plants, which is what gives them their salty flavor. Considered a vegetable, herb or an edible garnish, they are found in nature in the salt marshes and thrive in saltwater with the right balance of nutrients. They can be eaten raw, blanched, sautéed, or cooked in a dish.
The study, which is part of FAU's Integrated Multi-Trophic Aquaculture system project to optimize sustainability and aquaculture production, has been testing three different substrates to grow the sea vegetables: sand, clay pebbles, and water only. The work is an ambitious system that produces multiple species simultaneously and is designed according to the premise that one "species' trash is another one's treasure." Greater sustainability has been the driver of aquaculture systems development at FAU's Harbor Branch, leading to advances that have included minimizing both water use through recirculation techniques and power use via improved efficiency.
In this latest study, the largest plant harvested was the saltwort, which was grown in the sand substrate and weighed almost two pounds. Approximately 100 pounds of the plants that were grown in the study came from six tanks in the experimental system. By the end of the study, researchers had grown a total of 187 plants, only losing two plants, which demonstrates their exceptional survival. The average edible portion from the plants ranged from 55 percent for the sea purslane to 72 percent for the sea asparagus and 75 percent for the saltwort. The plants did better overall in the sand substrate; were a greener color in the sand and clay treatments; and were lighter green when grown in the water only tanks.